1. Field of the Invention
The present invention relates to a display apparatus. More particularly, the present invention relates to a display apparatus capable of improving lateral visibility of the display apparatus.
2. Discussion of the Background
A liquid crystal display (LCD) represents a limited viewing angle as compared with other display apparatuses. In order to improve the viewing angle, various driving schemes such as a Patterned Vertical Alignment (PVA) mode, a Multi-domain Vertical Alignment (MVA) mode and a Super Patterned Vertical Alignment (SPVA) mode have been suggested to drive the LCD.
An SPVA-mode LCD includes pixels that each have two sub-pixels, and each sub-pixel includes a main pixel electrode and a sub-pixel electrode. Different sub-voltages are applied to the main pixel electrode and the sub-pixel electrode to form domains having different gray scales in the pixel. Since human eyes looking at the LCD tend to perceive an intermediate value of the two sub-voltages, degradation of the lateral viewing angle caused by distortion of a gamma curve at a level below an intermediate gray scale is prevented, so that the lateral visibility of the LCD is improved.
The SPVA-mode LCD is classified into a Coupling-Capacitor (CC) type LCD and a Two-Transistors (TT) type LCD according to a driving scheme thereof. The CC type LCD adopts a driving scheme in which a coupling capacitor is added between the main pixel electrode and the sub-pixel electrode to drop a data voltage applied to the sub-pixel electrode such that a voltage applied to the sub-pixel electrode is lower than a voltage applied to the main pixel electrode. The TT type LCD adopts a driving scheme in which two transistors are used to apply a main pixel voltage and a sub-pixel voltage having different voltage levels to the main pixel electrode and the sub-pixel electrode, respectively.
Since the CC type LCD includes fewer transistors as compared with the TT type LCD, the CC type LCD has advantages in terms of power consumption. However, since the sub-voltage applied to the sub-pixel electrode is lower than input data voltage, brightness of the LCD is lowered at a white gray scale.